Given the task definition and input, reply with output. In this task, we ask you to rewrite a sentence in simple English without changing its general meaning. Essentially, you want to make the sentence easier to read by using simpler words, utilizing more straightforward sentence structures, and omitting non-essential information etc.

It consists of two parts : " endo- " and " -orphin " ; these are short forms of the words " endogenous " and " morphine " , intended to mean " a morphine-like substance originating from within the body " .

Their name has two parts : " endo- " and " -orphin " ; these are short forms of the words " endogenous " and " morphine " .